Saving lives and saving dollars

By: Roads & Bridges

After observing what could have been a fatal accident on I-75 in Bradenton, Fla., Matthew Schindler, president of Cloverleaf Corp. in Tampa, has a greater appreciation for a product he sells—a high-tension barrier system.

Schindler was recently traveling southbound on I-75 when he heard posts breaking in the median. “I recognized the sound,” he said, “because I’d viewed the crash tests. But I didn’t expect to see a live demonstration.” As he looked to his left, he saw a northbound vehicle hitting the cable.

The motorist told him she was traveling 70 mph in the left lane when a vehicle in the center lane merged into hers. She slammed on her brakes, went into the grass and hit the cable barrier. Neither she nor her two passengers were injured, and the car sustained relatively minor damage. Schindler noted that had the accident occurred two years earlier, before the barrier was installed, the motorist might have “crossed the median and had a serious head-on collision . . . with me.”

“Fortunately,” he said, “the Nucor barrier system performed exactly as it was designed.” The U-channel steel posts broke away at the ground, and the cables maintained height upon impact, decelerating the vehicle and preventing it from careening into oncoming traffic.

To address its state’s historically high traffic fatality rates, the Florida Department of Transportation (FDOT) began developing a Strategic Highway Safety Plan in 2001, identifying areas where the opportunity for improvement was greatest. A study of crash trends from 2000 to 2004 showed that more than half of Florida’s fatalities and serious injuries resulted from lane departures, including median crossovers. FDOT is implementing various measures, such as high-tension barrier systems, to mitigate such accidents. Cable barrier systems have proven to reduce median crossover fatalities in some states by as much as 90%.

On I-75 between Bradenton and Fort Myers, the U.S. High-Tension system manufactured by Nucor Steel Marion Inc. in Ohio was chosen for its cost-effectiveness (up to 75% less than other systems) and ease of installation and maintenance. Amy Burlarley-Hyland, P.E., director of the asset management division of DBI Services LLC, FDOT’s asset maintenance contractor, said, “Our crews love the system because it can often be repaired within 30 minutes. I’ve had experience with many median barrier systems, and this is by far the simplest to repair after a hit.”

According to FDOT Chief Safety Officer Marianne Trussell, while the number of injuries resulting from lane departures rose slightly in 2005 and 2006 (due to driver error, secondary crashes and other conditions), the number of fatalities is declining. Florida’s total traffic fatality rate decreased 4.7% in 2006 to 1.65 per 100 million vehicle-miles traveled. According to Schindler, that reduction is thanks in part to the safety systems installed in the medians.